DIY Honda ECU Repairs- P30 P08 P27

[EF_Hatch]

nope i didnt, engine is fresh built with high compresion 12:1 and light camshaft. i didnt rev it to high neither because right now it "runs" lean, of course i can't datalog with solid cel. i just started up engine for 30-50 seconds only.. tried many times with same problem..

 

[redzuana]

Hi,
Sorry because I cannot find a Toyota forum on ECU. So I come here. Can anyone or someone you know fix or diagnose my ABS ECU Toyota Altis 89540-12571? I suspect that the ECU got issue after the workshop did some ICE work and HKS power regulator to my car. Can PM or email the contact to me at [email protected]. Thanks.

 

[EF_Hatch]

Hi again E-tech, finally p06 trashed, i dont know why but after to work fine suddenly got solid cel...well, today i chiped a p28 manual ecu, i have to say i bought a moates engine sim for testing it faster,ok ,everything was fine, tested once i cleaned all solders,etc and worked fine with engine simu, vtec working,etc, had to go out , then im back for ago some minutes and tested it again, still worked good, but after 3 try, i get solid cel, i can't read code, it's solid cel, it worked good!!! i dontknow why right now is damaged, how's possible that?, cutted j1 and same problem, and after many trys, with j1 works ok again! but still solid cel with ji jumped, according engine sim, not pass 4.000rpm, ive been reading all thread and people talk about caps, what you means with all caps? ive seen about IC12 too, the p06 damaged, ic12 was too hot, not sure if that was the problem but right now i want to fix problem with p28 since that's my only ecu i have right now and wanna start and tune a car.

Hope your help, thank in advance E-Tech!!

 

[EF_Hatch]

im here again, ok, today i tested it and it works! but it's weird because after about 4-5 seconds get solid cel..not sure where would be the problem..tomorrow i will test it in the car but if you maybe can know where could be the problem please feel free to ask me for testing anything. Thanks E-Tech!

 

[E-Tech]

Hatch... after 4-5secs then got good chance to pull the error code.
With error code it is easier to troubleshoot....

 

[EF_Hatch]

thanks for your reply E-Tech, i do but it's solid cel..i can make a video with engine simulator and you can check what ecu do. if you need more pictures of this P28 i will do too.

Thanks alot!

 

[E-Tech]

thanks for your reply E-Tech, i do but it's solid cel..i can make a video with engine simulator and you can check what ecu do. if you need more pictures of this P28 i will do too.

Thanks alot!

I dun test with engine sim... i normaly test in my car...
Cel after car starts 3-4 secs will surely hv code.

Go do it in the car and telk me the code.

Do post a good picture of the top side of the board.
Pls mail to [email protected]...

Tq

 

[EF_Hatch]

Thanks, mail sent!!!

 

[ryand]

Hi e-tech,

been a long time since i logged in.

I got this p08 ecu rechipped. at key on feul pump prime and relay click, check engine light goes off. however after few seconds. check engine is ON. try to code it. it does not blink steady CEL.

I tried disconnecting J1 but same results. key ON, check engine goes OFF, then after a while steady CEL. No codes thrown

thanks

 

[E-Tech]

Hi e-tech,

been a long time since i logged in.

I got this p08 ecu rechipped. at key on feul pump prime and relay click, check engine light goes off. however after few seconds. check engine is ON. try to code it. it does not blink steady CEL.

I tried disconnecting J1 but same results. key ON, check engine goes OFF, then after a while steady CEL. No codes thrown

thanks

Can start? Can rev past 4000rpm?

 

[ryand]

Can start? Can rev past 4000rpm?

yes it can start but have not tried reving since i dont know the problem yet..

 

[E-Tech]

yes it can start but have not tried reving since i dont know the problem yet..

You are most likely in limp mode or backup mode.. it will not rev pass 4000.
If the ecu was good before chipping then you hv damaged the copper
trace some where...

Anyway need to be sure so slowing rev see if can pass 4000 to be
sure if u r in limp mode.

Btw hv u change all the caps? Any "brown" marks near the caps?

 

[ryand]

it worked before rechip then suddenly it threw a CEL.

i checked continuity from IC1 to hc373 to sst socket including test point. all was good.

220uF 35V cap damage the board but im sure there was no short or open trace near the area.

usually when there is an open trace, its a steady CEL upon key ON

However, for this po8 ecu, after key ON check engine goes off then comes back on after 5 sec. with no codes just steady CEL

I tested it with and without J1 shorted.

 

[E-Tech]

it worked before rechip then suddenly it threw a CEL.

i checked continuity from IC1 to hc373 to sst socket including test point. all was good.

220uF 35V cap damage the board but im sure there was no short or open trace near the area.

usually when there is an open trace, its a steady CEL upon key ON

However, for this po8 ecu, after key ON check engine goes off then comes back on after 5 sec. with no codes just steady CEL

I tested it with and without J1 shorted.

Anyway do the rev test....
Email me some good pictures too.
Tq

 

[ryand]

I did a rev test its goes past 4k rpm

 

[ryand]

Anyway do the rev test....
Email me some good pictures too.
Tq

did the rev test and it goes past 4k rpm.

when the ecu uses the external chip ( j1 shorted) the main relay tics only once, and the fuel pump never stops running,,

its like ecu is not stopping the second relay inside the main relay however,

when i remove the chip and J1, the main relay tics twice then CEL goes OFF, after 5-6 sec. CEL ON, not throwing codes,


I tried to pull one sensor plug air temp sensor, and key ON, relay works, pumps stops, CEL ON, did the diagnotic plug, threw code 10. so ecu is working

check sta413a - good
injectors works
car starts

badly need help.

thank you in advance

 

[E-Tech]

did the rev test and it goes past 4k rpm.

when the ecu uses the external chip ( j1 shorted) the main relay tics only once, and the fuel pump never stops running,,

its like ecu is not stopping the second relay inside the main relay however,

when i remove the chip and J1, the main relay tics twice then CEL goes OFF, after 5-6 sec. CEL ON, not throwing codes,


I tried to pull one sensor plug air temp sensor, and key ON, relay works, pumps stops, CEL ON, did the diagnotic plug, threw code 10. so ecu is working

check sta413a - good
injectors works
car starts

badly need help.

thank you in advance

Hi
If the ecu was okay before chipping then
Remove the socket and reconfirm all copper
trace.
If before chipping also like that then it
is a more complex problem. Hv seen something
like that before and hv not found the cause
only suspect the main processor.
Tq

 

[ryand]

thank you e-tech

copper trace are good, i did the continuity test several times. and diagnostic test for sensors ( tps, iat, etc ) will not work if there the board have an open or shorted trace.

tnx again, i work on it some more but more likely this will be spare parts ecu

 

[Vincew]

My b16a started to give cel code 9 when cold start up. After driving when water temp goes to 90degC, turn off the engine and restart; the cel disappears and car run normal. I have swapped distributor but same problem. I then check the resistance of the distributor connection and I get 376 ohm (spec is 350 ohm to 700 ohm). Check the wire by pulling the connector off from ecu and probe contact, also get 376ohm. Now I have no spare ecu to try swap. I suspect it is ecu dry solder joint issue but I do not know which component I should reflow for cel 9 and how to probe the ecu to make us ok. Please help to advise, thank you.

 

[E-Tech]

My b16a started to give cel code 9 when cold start up. After driving when water temp goes to 90degC, turn off the engine and restart; the cel disappears and car run normal. I have swapped distributor but same problem. I then check the resistance of the distributor connection and I get 376 ohm (spec is 350 ohm to 700 ohm). Check the wire by pulling the connector off from ecu and probe contact, also get 376ohm. Now I have no spare ecu to try swap. I suspect it is ecu dry solder joint issue but I do not know which component I should reflow for cel 9 and how to probe the ecu to make us ok. Please help to advise, thank you.

Hi...
Change the capacitors first (7-8 pcs) and clean up the board.